1. Field of Invention
The invention relates to an accelerator opening setting apparatus, a method thereof and a motor vehicle equipped with the apparatus. More particularly, the invention relates to an automotive accelerator opening setting apparatus for setting the degree of opening of an accelerator in accordance with the amount of operation of an accelerator pedal, and a motor vehicle equipped with the apparatus.
2. Description of Related Art
In a motor vehicle of the aforementioned type, a throttle valve of an internal combustion engine is electronically controlled so as to achieve a degree of throttle opening corresponding to a driver's request and to the state of operation of the internal combustion engine (disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 9-42032). In this motor vehicle, a target degree of throttle opening is set on the basis of a driver's operation of an accelerator, and the throttle valve is driven and controlled by an electric motor so as to achieve the target degree of throttle opening. If the fluctuation in the amount of an accelerator operation becomes small, it is determined that a steady engine operation is reached, and the control gain is reduced so as to facilitate the steady engine operation.
However, in this type of motor vehicle, the accelerator needs to be frequently operated in order to maintain a cruising speed of the vehicle after an accelerating or decelerating operation. When the amount of the accelerator operation is greatly changed for acceleration or deceleration, the degree of opening of the throttle valve is controlled to an increased or decreased degree corresponding to the amount of the accelerator operation. To establish a cruising run from this state, it is necessary to operate the accelerator so as to set an amount of the accelerator operation suitable to the cruise. However, it is not easy to immediately set the amount of an accelerator operation, and therefore the accelerator needs to be frequently operated. The control gain is set small at the time of small fluctuations in the amount of the accelerator operation. However, when a cruise is intended following an accelerating or decelerating state, the amount of accelerator operation is great, so that the control gain is not set small. In that case, therefore, frequent accelerator operations are needed.